Bicycle component and method for manufacturing such a component

ABSTRACT

A bicycle component is provided comprising an elongated body consisting of structural fibers incorporated in a matrix of polymeric material and having, in an end part thereof, a seat for the mechanical coupling of the component with an element of the bicycle. Also provided in the zone between the seat and the end of the body is a continuous layer of structural fibers which surround the seat and which ensure mechanical continuity in the aforementioned zone. The central part of the component comprises at least one first layer formed of continuous structural fibers incorporated in a matrix of polymeric material and at least one second layer formed of small pieces of structural fibers incorporated in a matrix of polymeric material and arranged randomly inside the layer, such layers overlapping each other.

FIELD OF INVENTION

The present invention relates to a bicycle component that isparticularly suitable for use in the assembly of bicycle parts that dealwith high specific pressures. The invention also relates to a method ofmanufacturing such a component.

Although the exemplary component described is a pedal crank, theinvention also extends to other bicycle components with requirementssimilar to those of a pedal crank, for example, a seat tube.

BACKGROUND

According to the prior art, different types of pedal cranks are known,having different shapes, materials and constructive techniques in orderto achieve the object of reducing as much weight as possible and, at thesame time, ensuring, if not even improving, the characteristics ofstrength and reliability.

The trend towards manufacturing lighter components has led to the use ofcomposite materials, in particular those formed of sheets of plasticresin material, incorporating structural fibers that contributeconsiderably to the structural strength of the component.

A known solution which uses the aforementioned technique is shown inpublished European Patent Application No. EP 1 281 609A currentlyassigned to Campagnolo S.r.l., wherein the body of the component isobtained by molding a thermosetting composite material inside a moldwith metal inserts therein.

A suitable composite material is described in U.S. Pat. No. 4,339,490.Sheets formed of a resin matrix have differently shaped small pieces ofstructural fibers, of a size between 1 and 100 mm, orientated randomlyinto the sheet. The use of such a type of composite material for moldingprovides a compromise between obtaining good strength characteristics,typical of the structural fibers, and the need to keep a sufficientfluidity during molding. The size of the small pieces, allows thecomposite material to flow sufficiently uniformly inside the mold,creating a homogenous pedal crank body.

This molding technique, however, has some drawbacks. The moldingtechnique used provides for arranging a predetermined amount ofcomposite material in the central zone of the mold and, during themolding step, making such a composite material flow until the entiremold is filled, even in the end areas with the arranged metal inserts.During the molding step, the composite material flows around the metalinserts following two distinct flow paths that meet near the end of thepedal crank, completely encasing the inserts.

First, the two-pronged flow causes a disadvantageous area ofdiscontinuity in the joint points of the two flows. Second, adisadvantage stems from the greater fluidity of the resin with respectto that of the structural fibers and due to the long route (from thecenter to the end of the mold), the end zones of the pedal crank have agreater percentage of resin with respect to the percentage in the restof the pedal crank and, consequently lower strength with respect to therest of the body. Third, a specific drawback encountered in pedal cranksobtained by molding composite material having small pieces of structuralfibers is the breakage of the pedal crank in its center area. Theoccurrence of such a drawback is due to the fact that such a compositematerial with small pieces does not ensure sufficient strength in suchan area of the pedal crank.

Since the ends of the pedal crank are subjected to substantial stressduring pedaling, the two aforementioned drawbacks can lead to undesiredbreakage of the pedal crank in these areas.

SUMMARY

In a first aspect, the invention relates to a bicycle componentcomprising an elongated body having spaced apart first and second ends,each end defining a seat for mechanical coupling with an element of thebicycle. The component further comprises at least two layers ofstructural fibers incorporated in a matrix of polymeric material, atleast one of the layers having randomly arranged structural fibers. Atleast one of the layers of structural fibers partially surround each ofthe seats, establishing mechanical continuity between them.

In another aspect, the invention comprises a method for manufacturing abicycle component comprising an elongated body consisting of structuralfibers incorporated in a matrix of polymeric material and having, in anend part thereof, a seat for mechanical coupling with an element of thebicycle, said method comprising the steps of:

-   -   arranging, at a first half of a mold, a continuous layer of        fibers in a configuration such as to at least partially surround        a seat located at a end of the mold;    -   closing a second half of the mold above said first half;    -   inserting, from an opening at said second half of the mold, a        composite material comprising small lengths of structural fibers        incorporated in a matrix of polymeric material and arranged        randomly inside the matrix;    -   inserting, in said opening at said half of the mold, a plunger        and subjecting said composite material to a pressure to allow        the recess defined by the mold to be filled;    -   increasing the temperature of the mold up to a value which        allows the reticulation of the polymeric material of said        matrix;    -   moving the two parts of the mold apart and removing said        component.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention shall becomeclearer from the description of some preferred embodiments, given withreference to the attached drawings, where:

FIG. 1 represents a schematic isometric view of the component of theinvention.

FIG. 2 represents a section view from above of the component of FIG. 1.

FIG. 3 represents an alternate embodiment of the component of FIG. 1.

FIG. 4 represents an elevated section view of the component of FIG. 3.

FIGS. 4A, 4B and 4C represent elevated section views of alternateembodiments of the component of FIG. 3.

FIG. 5 represents another alternate embodiment of the component of FIG.1.

FIGS. 6 to 11 represent different isometric views of the semi-finishedproduct of the invention.

FIG. 12 represents an exploded isometric view of the mold used formanufacturing the component of the invention.

FIG. 13 represents an isometric view of a detail of FIG. 12.

FIG. 14 represents an exploded isometric view of a mold used formanufacturing an alternate embodiment of the component of the invention.

FIG. 15 represents an isometric view of an alternate embodiment relativeto the progression of the continuous layers of structural fibers in abranched pedal crank.

FIG. 16 represents a plan view of FIG. 15.

FIG. 17 represents another alternate embodiment relative to theprogression of the continuous layers of structural fibers in a branchedpedal crank.

FIG. 18 represents an isometric view of a further alternate embodimentrelative to the progression of the continuous layers of structuralfibers in a branched pedal crank.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, the layers of continuous structural fibers 13and 14 are made with unidirectional fibers orientated substantiallyparallel to the middle plane π through the component, in this case apedal crank 1. Middle plane π is a substantially flat surface thatintersects the pedal crank 1 longitudinally and divides it substantiallyin half along its height H. Given the typical shape of the pedal crank1, such a surface is slightly curved when one moves from one end 11 tothe other 12 of the pedal crank 1.

Typically, said continuous structural fibers are chosen from the groupconsisting of carbon fibers, glass fibers, boron fibers, aramidicfibers, ceramic fibers, carbon fiber being preferred.

As it can be clearly seen in FIG. 2, the layers of continuous structuralfibers 13 and 14 surround the end zones 9 and 10 of seats 5 and 6, in asingle closed loop 15 of unidirectional fibers that extendlongitudinally along the body 2 of the pedal crank 1. This configurationcould be different, like for example a series of unidirectionalstructural fibers surrounding the two seats 5 and 6 according to atypical “figure-eight” configuration.

In FIG. 2, the layers of continuous structural fibers 13 and 14 areprovided only in a part of the thicknesses S1 and S2 of the end zones 9and 10 and can, at most, also be reduced to a single layer. Such layers13 and 14 are provided only for a part of the height H of the pedalcrank component 1 and are confined in height by means of an annularretainer element 16, coaxial to the insert 7.

The arrangement of a limited number of layers 13 and 14 of fibers in thepedal crank 1 implies that the inserts 7, 8 are substantially coveredwith the composite material 18 with which the body 2 of the pedal crank1 is formed, as can be seen more clearly in FIG. 2.

A different solution is shown in FIGS. 3 and 4, wherein the layers ofcontinuous structural fibers 33 and 34 substantially fill thethicknesses of both S1 and S2 of the end zones 29 and 30 of the pedalcrank 20. In this solution the composite material 38, with which thebody 2 of the pedal crank 1 is formed, is confined inside loop 35defined by the layers of continuous fibers 33 and 34.

The alternate embodiments shown in FIG. 4A differ from the solutionshown in FIG. 4 for the fact that the body 2 has a core C filled with amaterial having a lower specific weight than the composite material 38.

In the embodiments shown in FIG. 4B and FIG. 4C the core C is removedafter molding, so that the weight of the pedal crank is reduced.

FIG. 5 shows an alternate embodiment of the arrangement of the layers ofcontinuous structural fibers 53 and 54 wherein the layers completely andseparately surround the two seats 45 and 46 and the corresponding metalinserts 47 and 48.

As can be seen with reference to FIGS. 1-2, the component 1 has, at itsend parts 3 and 4, respective seats 5 and 6 for mechanical coupling witha bottom bracket and with a pedal of the bicycle. The seats 5 and 6incorporate cylindrical metal inserts 7 and 8 in which holes, not shown,are formed to connect the inserts 7 and 8 the bottom bracket and to thepedal, respectively.

In an alternate embodiment, the seats 5 and 6 comprise a hole of asuitable shape adapted to allow the direct connection of the pedal crankto the bottom bracket and to the pedal or else the subsequent insertionof metal inserts.

In the two end zones 9 and 10 of the pedal crank 1, between the seats 5and 6 and ends 11 and 12 of the body 2 of the pedal crank 1, there arelayers of continuous structural fibers 13 and 14 that surround the endzones 9 and 10 of the seats 5 and 6, as previously described. Suchlayers of continuous structural fibers 13 and 14 ensure that in such endzones 9 and 10 there is structural and mechanical continuity.

In different embodiments, the layers of continuous structural fibers cantake different shapes and sizes. For example, such layers can extend, atthe end zone, for the entire height H of the pedal crank 1. Moreover,such layers can be made of interwoven structural fibers according to atleast two incident directions to make a fabric. In a preferredembodiment, such a fabric comprises a majority of fibers orientatedaccording to a direction parallel to the middle plane of the pedal crank1. Finally, it is possible that in further embodiments there are aplurality of layers of continuous structural fibers, according to anycombination of the continuous layers described above.

The pedal crank 1, and specifically its elongated body 2, is formed froma semi-finished product, indicated as 60 in FIG. 6, consisting of threelayers. Each of the layers is formed as a sheet of material. As usedhereinafter in the description and claims, the term “sheet” refers to adefined thickness of material forming either an individual layer, or oneof a plurality of independent or joined layers of a structure. One layer61 is formed of small lengths of structural fiber 61 a incorporated in amatrix of polymeric material and randomly arranged within the layer 61and two layers 62 and 63 are formed of continuous structural fibers 62 aand 63 a which are incorporated in a matrix of polymeric material andorientated according to directions which are preferably angled relativeto each other. The layers 61, 62 and 63 overlap one another and give thesemi-finished product 60 characteristics of structural strength throughthe unidirectional fibers 62 a and 63 a and good characteristics offluidity through the sheeted structure 61 a, this last characteristicbeing exploited in the molding step of the pedal crank 1.

With regards to the continuous structural fiber, the small lengths ofstructural fibers are chosen from the group consisting of carbon fiber,glass fibers, boron fibers, aramidic fibers, and ceramic fibers, carbonfiber being preferred.

The polymeric material may be a thermosetting plastic material or athermoplastic material.

The arrangement and number of layers, as well as the directions of thestructural fibers, can be chosen according to the particular propertiesof desired structural strength of the component. For example, in FIG. 7layer 61 is arranged between layers 62 and 63.

The embodiment of FIG. 8 differs from that of FIG. 6 in that theunidirectional fibers 72 a and 73 a are incorporated in the matrix ofpolymeric material of respective layers 72 and 73 in complementarydirections and are respectively orientated at +90° and 0°.

In FIG. 9 the semi-finished product comprises a layer of small lengthsof structural fibers 61 a incorporated in a matrix of polymeric materialoverlapping a single layer 63 formed of continuous structural fibers 63a orientated on a bias within layer 63.

In FIG. 10 the semi-finished product comprises a layer of small lengthsof structural fibers 61 a and a layer 81 in which the continuousstructural fibers 81 a are arranged according to two incident directionsand form a fabric configuration.

Finally, in FIG. 11 a semi-finished product formed of five layers isshown. Two layers 91 and 93 are formed of small lengths of structuralfibers incorporated in a matrix of polymeric material intercalated inthree layers 92, 94 and 95 formed of continuous structural fibers ofadjacent layers in which the fibers are orientated at an angle relativeto each other.

The semi-finished product 60 used for manufacturing the body 2 of thepedal crank 1, according to any of the above illustrated embodiments andall other possible configurations, are preferably rolled around arolling axis before the molding step, as described below. This allowsthe characteristics of unidirectional strength of the structural fibersto be spatially distributed.

Referring now to FIG. 12, the method for manufacturing the pedal crank20 shown in FIG. 3 is described. However, it should be understood thatthe same method can be used for the other embodiments shown ordescribed, for example those of FIGS. 1 and 5.

The method provides for the use of a mold 100 which comprises threeparts, two half-shells 101 and 102 and a plunger 103. The upperhalf-shell 102, as seen more clearly in the bottom view of FIG. 13, hasa through-opening 104 which allows the passage and the sliding of apress element 105 of the plunger 103.

A first step of the method provides for the formation of an intermediateproduct 110 comprising the inserts 7 and 8 on which the layers ofcontinuous unidirectional structural fibers are wound in a closed loopconfiguration 35. Such an intermediate product 110 can be realized, forexample, by winding a long fiber around the inserts 7, 8 in a number oflayers sufficient to obtain a desired thickness and height. Inparticular, the arrangement of the fibers around the insert 7 is definedthrough retainer loop 16 which confines them in an upper portion of theinsert 7. Experience has demonstrated that it is precisely such an areathat is subjected to the greatest torsional stress during pedaling, thusrequiring a greater structural strength.

The intermediate product 110 thus obtained is placed inside the lowerhalf-shell 101 above which the upper half-shell 102 is closed so thatits shapings 102 a and 102 b (FIG. 13) are in contact with the heads ofthe metal inserts 7 and 8.

When the half-shells 101 and 102 of mold 100 are closed, thesemi-finished product 60 previously wound around the rolling axis A isinserted in through opening 104. The winding of the semi-finishedproduct 60 is arranged so that its outer surface consists of layer 63formed of unidirectional fibers 63 a. The semi-finished product 60 ispre-heated to ease the subsequent molding.

After its insertion in the mold 100, the wound semi-finished product 60is then located in the zone defined between the inserts 7 and 8 and theinner part of the loop 35. When the plunger 103 is lowered, the pressertool 105 slides inside the opening 104 of the upper half-shell 102urging the semi-finished product 60 inside the mold 100. During such amolding step, the semi-finished product 60 flows into and uniformlyfills the recess defined by the two half-shells 101 and 102. The closedloop configuration 35 of the unidirectional fibers allows them to keeptheir continuous configuration even during molding, since the pressureforces applied by the composite material which constitutes thesemi-finished product 60 are uniformly distributed along the loop 35.After insertion of the presser tool 105, the mold 100 is heated,according to known techniques, and the materials inside of mold 100polymerizes in the desired pedal crank structure. Finally, the mold 100is opened and the pedal crank is removed.

It is clear that for the described method any of the semi-finishedproducts described above with reference to FIGS. 6-11 can be used,possibly even in a non-wound configuration. If one wishes to manufacturethe pedal crank according to the shape shown in FIG. 5, it is thenadvisable for the intermediate product, in this case comprising theinserts on which the unidirectional fibers are individually wound, toundergo a prepolymerization treatment, so that the subsequent moldingdoes not modify the shape of the wound fibers.

Alternatively, the component may further comprise a core C as depictedin FIGS. 4A, 4B and 4C. In the manufacture of the component of FIG. 4A,a mold 100 is provided, having first and second portions 101, 102 andplunger 103 as shown in FIG. 12. An intermediate product 110 is firstformed comprising first and second inserts 7, 8, about which layers ofcontinuous unidirectional structural fibers are wound in a closed loopconfiguration 35. A core C is then arranged in the area within theclosed loop of unidirectional structural fibers.

Once the intermediate product 110 is in position in the first moldportion 101, the second portion 102 is closed above the first portion sothat shapings 102 a and 102 b contact the upper portions of the inserts7, 8. When the first 101 and second 102 mold portions are closed aboutthe intermediate product 110, a composite material 38 is inserted intoan opening 104 of the second portion 102 of the mold 100. The compositematerial 38 comprises small lengths of randomly arranged structuralfibers incorporated in a matrix of polymeric material. Next, the plunger103 is lowered, to force presser 105 into the opening 104 of the secondmold portion 102. The presser 105 forces the composite material 38 intothe mold 100. During this step the composite material 38 flows into themold 100 and uniformly fills the recess defined by the first and secondmold portions 101, 102 thereby enclosing the core C. With the presser105 inserted, the mold is heated to a temperature sufficient topolymerize the composite material 38, thereby producing the desiredpedal crank structure. The mold is then opened and the pedal crank isremoved. The core C is made of a material having a lower specific weightthan the composite material 38. The weight of the pedal crank with thecore enclosed is less than the weight of the pedal crank completely madeof composite material.

In the manufacture of the component of FIG. 4B, a mold 100 is provided,having first and second portions 101, 102 and plunger 103 as shown inFIG. 12. An intermediate product 110 is first formed comprising firstand second inserts 7, 8, about which layers of continuous unidirectionalstructural fibers are wound in a closed loop configuration 35. A core Cmade of a removable material is then arranged in the area within theclosed loop of unidirectional structural fibers. The core helps tomaintain the position of the closed loop of unidirectional structuralfibers 35 and inserts 7, 8.

Once the intermediate product 110 is in position in the first moldportion 101, the second portion 102 is closed above the first portion sothat shapings 102 a and 102 b (FIG. 13) contact the upper portions ofthe inserts 7, 8. When the first 101 and second 102 mold portions areclosed about the intermediate product 110, a composite material isinserted into an opening 104 of the second portion 102 of the mold 100.The composite material 38 comprises small lengths of randomly arrangedstructural fibers incorporated in a matrix of polymeric material. Next,the plunger 103 is lowered, to force presser 105 into the opening 104 ofthe second mold portion 102. The presser 105 forces the compositematerial 38 into the mold 100. During this step the composite material38 flows into the mold 100 and uniformly fills the recess defined by thefirst and second mold portions 101, 102 thereby enclosing the core C.With the presser 105 inserted, the mold is heated to a temperaturesufficient to polymerize the composite material 38, thereby producingthe desired pedal crank structure. The mold is then opened and the pedalcrank is removed.

Small openings D1, D2 are formed to remove the core material from thecrank structure. The openings D1, D2 may be formed by drilling or otherknown methods. Two or more openings are preferred to allow for betterair exchange between the core and the ambient space which aids inremoving the core material. The core material may be sand, a powderedmaterial or a metallic alloy having a low melting point. A core of sandor powdered material can be removed from the crank by falling throughthe openings D1, D2 under the force of gravity. If a metallic alloy isused as the core, it may be removed simply by heating the crank abovethe alloy's melting point and allowing the melted core to flow throughthe openings D1, D2. Removal of the core material may also be expeditedby blowing high-pressured air or fluid through one of the openings. Oncethe core material has been removed, the openings are then sealed toprevent contaminants from entering the pedal crank. The weight of thepedal crank is further reduced with respect to weight of the pedal crankabove described by removal of the core material.

A similar method as above for manufacturing the pedal crank of FIG. 4Bcan be used for manufacturing the pedal crank of FIG. 4C. In this case,rather than a metal insert, a support is used for the winding of theunidirectional fibers. The support remains incorporated in the pedalcrank whereby a seat can be formed, by machining, for the insertion of ametal insert. In this embodiment, the removal of the core material takesplace through openings D3 and D4 before the insertion of the metalinsert.

FIG. 14 shows a variation of the mold shown in FIG. 12 which is used formanufacturing a branched pedal crank, commonly known as right pedalcrank. Such a method differs from the previous one in that thesemi-finished product, when inserted in the mold 200, covers the top ofthe metal insert intended for coupling with the bottom bracket. In thiscase, the metal insert can be accessed by machining away excess materialleft over from the molding process. Rather than the metal insert, asupport can be used for the winding of the unidirectional fibers. Thesupport remains incorporated in the pedal crank, through machining, fordirect coupling with a bottom bracket or the insertion of a metalinsert. It is also clear that the mold 200 can be modified so as toobtain a right pedal crank in which the insert intended for couplingwith the bottom bracket is also immediately accessible.

FIGS. 15 and 16 show the arrangement of the layers of continuousstructural fibers 413 a, 413 b, 413 c, 413 d for manufacturing anotherbranched pedal crank, commonly referred to as a right pedal crank.

In such a case it is desired to ensure high structural and mechanicalcontinuity of end parts 403 a, 403 b, 403 c, 403 d of the spokes ofintermediate product 400, four in this embodiment, where respectiveseats 405 a, 405 b, 405 c, 405 d which allow connection of front chainrings of the bicycle are formed. The seats 405 a, 405 b, 405 c, 405 dcan incorporate respective metal inserts in which suitable holes forconnection to the chain rings are formed. Alternatively, they cancomprise a hole of such a suitable shape and size as to allow the directconnection of the chain rings to the branches of the pedal crank. Forthe sake of simplicity of explanation, no insert is shown in thefigures.

As shown in FIGS. 15 and 16, the layers of continuous structural fibers413 a, 413 b, 413 c, 413 d partially surround the seats 405 a, 405 b,405 c, 405 d of the end parts 403 a, 403 b, 403 c, 403 d of the spokeswhich form an arc of circumference of about 180°. These layers are eacharranged in such a way as to form respective loops 415 a, 415 b, 415 c,415 d which close on a central zone 414 where the pedal crank has asuitable seat 406 for connecting to the bottom bracket.

The structural fibers thus arranged define an intermediate product 400which is star-shaped. As shown in FIG. 15, intermediate product 400 isadvantageously made through continuous winding, along suitable paths, ofcontinuous layers of unidirectional fibers. The intermediate product 400can be made either in the mold, i.e., inside the mold shown in FIG. 14,or it can be made separately using a mask which mirrors the shape of thespokes. The manufacturing of the intermediate product 400 separatelyallows for prior preheating of the fibers which allows them to be apre-shaped before the positioning in loco into the mold.

The intermediate product 400 is arranged within the mold 200 on a planeoverlapping the one in which the closed loop of structural fibers 15(represented in FIG. 2) is arranged, said fibers being arranged alongthe elongated body 2 of the pedal crank. The configuration thus obtainedallows a right pedal crank to be manufactured having the zones intendedfor coupling with a pedal as well as with a bottom bracket and the endsof the spokes with high structural and mechanical continuity.

In an alternate embodiment, shown in FIG. 17, each seat 405 a, 405 b,405 c, 405 d can be completely surrounded by structural fibers 413 a,413 b, 413 c, 413 d by using a closed loop configuration similar to thetype shown in FIG. 5.

The same result can be obtained by the manufacturing of a pre-formedproduct 500, as shown in FIG. 18, where the continuous layers ofstructural fibers associated with the spokes and with the main body areon the same plane and substantially constitute a single elementcomet-shape. As is the previous embodiment, the intermediate product 500can either be formed within the mold or can be formed separately using amask which mirrors the shape of the pedal crank.

1. A bicycle component comprising an elongated body having spaced apartend parts, each defining a seat for mechanically coupling said componentto an element of a bicycle, wherein there are multiple loops ofcontinuous structural fibers that are wrapped around said seats andstacked together to define an interior space having a length defined bya distance between said seats of said end parts and a height defined bya distance between a topmost one and a bottommost one of said loops ofcontinuous structural fibers, and filled entirely by a compositematerial formed by molding a plurality of overlapping sheets of fiberreinforced material wherein at least one of the sheets is formed ofsmall lengths of structural fibers.
 2. The component of claim 1, whereinsaid loops of continuous structural fibers are each made ofunidirectional fibers oriented according to a direction substantiallyparallel to a middle plane of the component.
 3. The component of claim1, wherein said loops of continuous structural fibers surround theentire area between said seat and said end.
 4. The component of claim 1,wherein said seat comprises a metal insert for coupling the component toan element of the bicycle.
 5. The component of claim 1, wherein thecomponent comprises an annular retainer element to confine said loops ofcontinuous structural fibers.
 6. The component of claim 1, wherein saidloops of continuous structural fibers are confined in the end zone ofthe component for a part of a thickness of the end zone.
 7. Thecomponent of claim 1, wherein the component comprises at a second endpart spaced apart from said first end part, a second seat for themechanical coupling with a second component of the bicycle and whereinbetween said second seat and said second end part said loops ofcontinuous structural fibers at least partially surround said secondseat to ensure mechanical continuity between said first and secondseats.
 8. The component of claim 7, wherein said loops of continuousstructural fibers surround said first and second seats forming a closedloop.
 9. A bicycle component comprising an elongated body formechanically coupling to at least one element of a bicycle and fortransmitting force, wherein said elongated body comprises spaced apartend parts, each defining a seat for mechanically coupling said componentto said at least one element of a bicycle, and multiple loops ofcontinuous structural fibers that are wrapped around said seats andstacked together to define an interior space having a length defined bya distance between said seats of said end parts and a height defined bya distance between a topmost one and a bottommost one of said loops ofcontinuous structural fibers, said interior space filled entirely by acomposite material formed by molding at least one first layer formed ofcontinuous structural fibers incorporated in a matrix of polymericmaterial and at least one second layer formed of small lengths ofstructural fibers incorporated in a matrix of polymeric material andarranged randomly inside said at least one second layer, said at leastone first layer and at least one second layer overlapping each other.10. The component of claim 9, wherein said continuous structural fibersof said at least one first layer are unidirectional fibers.
 11. Thecomponent of claim 9, wherein the composite material further comprises amolded third layer of continuous structural fibers formed ofunidirectional fibers arranged in a direction complementary to thedirection of said unidirectional fibers of said at least one firstlayer.
 12. The component of claim 11, wherein said complementarydirections of said unidirectional fibers of said at least one first andthird layers are +45° and −45° respectively.
 13. The component of claim11, wherein said at least one first layer, said at least one secondlayer and said third layers are arranged one next to the other beforemolding and in that said at least one second layer is not between theother two layers.
 14. The component of claim 13, wherein said at leastone first layer, said at least one second layer and third layer ofstructural fibers are rolled along a rolling axis before molding so thatsaid at least one first layer or said at least one second layer are onthe outside in a rolled configuration.
 15. The component of claim 9,wherein said at least one first layer and said at least one second layerare rolled around each other before molding.
 16. A bicycle componentcomprising an elongated body having a first end and a second end, andhaving, in each of said first and second ends, a seat for mechanicallycoupling the component with an element of a bicycle, wherein multipleloops of continuous structural fibers wrap around said seats of saidfirst and second ends forming a closed loop and at least partiallysurrounding said seat to ensure mechanical continuity, said loops ofcontinuous structural fibers being stacked together to define aninterior space having a length defined by a distance between said seatsof said first and second ends and a height defined by a distance betweena topmost one and a bottommost one of said loops of continuousstructural fibers, said interior space filled entirely by a compositematerial formed by molding at least one first layer formed of continuousstructural fibers incorporated in a matrix of polymeric material and atleast one second layer formed of small lengths of structural fibersincorporated in a matrix of polymeric material and arranged randomlyinside the second layer, said at least one first layer and at least onesecond layer overlapping each other.
 17. A bicycle crank arm comprising:an elongated body having spaced apart first and second ends that eachinclude a seat for coupling said bicycle crank arm to an element of abicycle, and multiple loops of continuous structural fibers that wraparound said seats of said first and second ends and are stacked togetherto define an interior space having a length defined by a distancebetween said seats of said first and second ends and a height defined bya distance between a topmost one and a bottommost one of said loops ofcontinuous structural fibers, said interior space filled entirely by acomposite material formed by molding at least two overlapping sheets ofstructural fibers incorporated in a matrix of polymeric material with atleast one of said sheets having the fibers randomly arranged, saidcomposite material being located between and in contact with said seatsto ensure mechanical continuity between the seats.
 18. A bicyclecomponent comprising an elongated body having a first end and a secondend, and having, in each of said first and second ends, a seat formechanically coupling the component with an element of a bicycle,wherein multiple loops of continuous structural fibers wrap around saidseats of said first and second ends at least partially surrounding saidseat to ensure mechanical continuity, said loops of continuousstructural fibers being stacked together to define an interior spacehaving a length defined by a distance between said seats of said firstand second ends and a height defined by a distance between a topmost oneand a bottommost one of said loops of continuous structural fibers, saidinterior space filled entirely by a composite material formed by moldingat least one first layer formed of continuous structural fibersincorporated in a matrix of polymeric material and at least one secondlayer formed of small lengths of structural fibers incorporated in amatrix of polymeric material and arranged randomly inside the layer,said at least one first layer and at least one second layer overlappingeach other.
 19. The component of claim 18, wherein the elongated bodycomprises: a predetermined configuration suitable for mechanicalconnection to a bicycle.
 20. A bicycle crank arm comprising: anelongated body having a first end part and a spaced apart second endpart, each one of the first and second end parts defines a seat formechanical coupling; multiple loops of continuous structural fibers thatwrap around said seats of said first and second end parts and at leastpartially surround said seats, said loops of continuous structuralfibers being stacked together to define an interior space filledentirely by a composite material formed by molding a plurality ofoverlapping sheets of fiber reinforced material, at least one of thesheets being formed of small lengths of structural fibers, said interiorspace having a length defined by a distance between said seats of saidfirst and second end parts and a height defined by a distance between atopmost one and a bottommost one of said loops of continuous structuralfibers.
 21. The component of claim 20, wherein each one of said loops ofcontinuous structural fibers is made of unidirectional fibers orientedaccording to a direction substantially parallel to a middle plane of thecomponent.
 22. The component of claim 20, wherein the continuousstructural fibers may be interwoven at least two incident angles orsubstantially parallel to a middle plane of the component.
 23. Thecomponent of claim 20, wherein said loops of continuous structuralfibers surround the entire area between said seats of said first andsecond end parts.
 24. The component of claim 20, wherein said loops ofcontinuous structural fibers completely surrounds said seats.
 25. Thecomponent of claim 20, wherein each one of said seats comprises a metalinsert for coupling the component to an element of the bicycle.
 26. Thecomponent of claim 20, wherein the component comprises an annularretainer element to confine said loops of continuous structural fibers.27. The component of claim 20, wherein said loops of continuousstructural fibers are confined in an end zone of the componentsurrounding said seats for a part of a thickness of the end zone. 28.The component of claim 20, wherein said loops of continuous structuralfibers surround said first and second seats forming closed loops. 29.The component of claim 20, wherein the component further comprises acore arranged within the elongated body.
 30. A bicycle crank armcomprising an elongated body having a first end part and a second endpart, each defining a seat for mechanically coupling said bicycle crankarm to an element of a bicycle, at least one of said seats having ametal insert, wherein there are multiple loops of continuous structuralfibers that wrap around said seats of said first and second end partsand at least partially surround said seat ensuring mechanical continuityin an end zone between said seat and an end of the body, said loops ofcontinuous structural fibers being stacked together to define aninterior space having a length defined by a distance between said seatsof said first and second end parts and a height defined by a distancebetween a topmost one and a bottommost one of said loops of continuousstructural fibers, said interior space filled entirely by a compositematerial formed by molding a plurality of overlapping sheets of fiberreinforced material, at least one of the sheets formed of small lengthsof structural fibers.
 31. A bicycle crank arm comprising an elongatedbody having a first end part and a second end part, said first andsecond end parts each comprising a seat for mechanically coupling saidbicycle crank arm to an element of a bicycle, wherein there are multipleloops of continuous structural fibers that wrap around said seats ofsaid first and second end parts and at least partially surround saidseat ensuring mechanical continuity in an end zone between said seat andan end of the body, said loops of continuous structural fibers beingstacked together to define an interior space having a length defined bya distance between said seats of said first and second end parts and aheight defined by a distance between a topmost one and a bottommost oneof said loops of continuous structural fibers, said interior spacefilled entirely by a composite material formed by molding a plurality ofoverlapping sheets of fiber reinforced material, at least one of thesheets having the fibers randomly arranged.
 32. A bicycle crank armcomprising: an elongated body with spaced apart end parts, each defininga respective seat for mechanically coupling the bicycle crank arm to oneof a bicycle pedal or crank shaft; the body including multiple loops ofcontinuous structural fibers that wrap around the seats and are stackedtogether to define an interior space having a length defined by adistance between said seats and a height defined by a distance between atopmost one and a bottommost one of said loops of continuous structuralfibers, said interior space filled entirely by a composite materialformed by molding a plurality of overlapping sheets of fiber reinforcedmaterial, at least one of the sheets formed of continuous structuralfibers and at least one of the sheets formed of small lengths ofstructural fibers.
 33. A bicycle crank arm having a body includingspaced apart end parts that each define a respective seat formechanically coupling said bicycle crank arm to an element of a bicycle;multiple loops of continuous structural fibers that wrap around saidseats and are stacked together to define an interior space having alength defined by a distance between said seats and a height defined bya distance between a topmost one and a bottommost one of said loops ofcontinuous structural fibers, said interior space filled entirely bymolding a thermoset fiber reinforced material.
 34. The crank arm ofclaim 33, wherein the thermoset fiber reinforced material comprises atleast one first sheet formed of small lengths of structural fibers andat least one second sheet formed of continuous structural fibers, the atleast one first sheet and the at least one second sheet overlapping eachother.